Lithium diisopropylamide → tert-butyl 4-[[2-[[(2S)-2-bicyclo[2.2.1]heptanyl]amino]-5-methyl-4-oxo-1,3-thiazol-5-yl]methyl]piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-((2S)-bicyclo[2.2.1]heptan-2-ylamino)-5-methylthiazol-4(5H)-one in anhydrous THF (30 mL) at −78° C. under N2 was added lithium diisopropylamide (Aldrich, 2.0 M in heptane/THF/ethylbenzene, 9.2 mL, 18.4 mmol). After stirring the reaction mixture at −78° C. for 1 h, a solution of 4-bromomethyl-piperidine-1-carboxylic acid tert-butyl ester (Pharma Core, 5.12 g, 18.4 mmol, 4.0 eq) in anhydrous THF (10 mL) was added under N2. The resulting reaction mixture was stirred at −78° C. for 4 h. The cooling bath was removed, and the reaction mixture was stirred at ambient temperature for ca. 18 h. Saturated NH4Cl was then added, and the THF was removed in vacuo. The residue was extracted with EtOAc (3×180 mL), and the combined organic layers were washed with saturated NaCl, dried over Na2SO4, filtered, and concentrated in vacuo. Flash column chromatography (silica gel, 0-60% EtOAc in hexane) afforded the title compound as an off-white solid (1.42 g). MS (ESI, neg. ion) m/z: 420 (M−H).

Provenance & Evidence